The mechanism of NADH synergism of NADPH-supported mixed function oxidase activity will be examined. Stoichiometry of reduced pyridine nucleotide consumption, oxygen consumption and substrate oxidation will be related, and discrepancies will be examined. Superoxide and hydrogen peroxide will be measured as well to assure their release is related inversely to the rate of drug metabolism. In addition, the mechanism of lipid peroxidation will be examined to discern whether another component is involved in the reaction, one that binds ferric ions. BIBLIOGRAPHIC REFERENCES: K. M. Robie, Y. N. Cha, R. E. Talcott, and J. B. Schenkman, Kinetic studies of benzpyrene and hydroxybenzpyrene metabolism. Chem.-Biol. Interactions, 12, 285-297 (1976). D. L. Cinti, S. R. Keyes, M. A. Lemelin, H. Denk, and J. B. Schenkman, Biochemical properties of rat liver mitochondrial aldehyde dehydrogenase with respect to oxidation of formaldehyde. J. Biol. Chem., 251. (1976).